It is "crucial" that the border between Northern Ireland and the Republic remains open and unfortified, Theresa Villiers has claimed.

The former Northern Ireland secretary, who quit front bench politics after declining Theresa May's offer of another Government position, said that there was a "reasonable chance" of keeping the crossing between the two countries open despite the Brexit vote.

Ms Villiers told the Murnaghan programme on Sky News that there had never been a "truly hard border" and that softer measures could be taken to combat illegal migration.

"What has encouraged me since the referendum result is that we have the new Prime Minister, the Brexit secretary, we have the Taoiseach in Ireland all saying we need to keep this border open - it is crucial.

"If you have both countries determined to keep the border open I think there must be a reasonable chance that we can do that."

Concerns about whether the free movement of people and goods will be impacted after Brexit have dominated the political discourse across the island since the vote.

The MP for Chipping Barnet said that there were "plenty of ways" to "crack down" on those who do not have the right to work in the UK without the need for "physical border checks".

"Of course we'd need measures to control EU migrants who came to the UK and chose to work if they didn't have appropriate entitlements but we've already got legal mechanisms to deal with that because we've criminalised working without proper permission," she told the programme.

"The best way to enforce rules of immigration is not through physical border checks at our land border with the Republic of Ireland, because as I say that's never been a properly enforced border, no one wants it on either side of the border to become a hard border again. There are other ways in which we can deal with the risks around illegal migration."

Ms Villiers also said she supported Prime Minister Theresa May's insistence that there will be no snap general election before 2020.

She said: "Obviously there is a temptation amongst commentators about early elections but I do think we need some stability... I think sort of pausing for breath, sticking to the timetable for a 2020 election does make a lot of sense."